Mario Luigi Partners Xbox

how much can i get for my nintendo ds and more at gamestop in credit?

My nintendo ds lite, a action replay,pokemon diamond,pokemon ruby ,sapphire,emerald,fire red ,and a mario and luigi partners in time

for playstation 2 rocky the game and baldur's gate dark alliance

and for xbox blinx the time sweeper and yu-gi-oh the dawn of destiny with an edge card